Motor vehicles and air

Motor vehicle contribution to air pollution

Sydney faces challenges in meeting the national air quality standards for ground level ozone (photochemical smog) and particle pollution. Vehicle exhaust emissions are major contributors to these pollutants.

Photochemical smog may be seen as a whitish haze formed from the action of sunlight on chemical compounds. In the Greater Metropolitan Region (GMR), two of the most significant components are volatile organic compounds and oxides of nitrogen. In Sydney, motor vehicles are responsible for 70% of emissions of oxides of nitrogen and 52% of volatile organic compounds.

Particle pollution is evident as the brown haze sometimes seen in the cooler months of the year. In winter, it is composed of airborne particles of which approximately 24% are from motor vehicles.

In most areas, motor vehicles are by far the major source of emissions. The main source of carbon monoxide is spark-ignition motor vehicles (petrol-fuelled); much smaller quantities are produced by compression-ignition (diesel-fuelled) vehicles and other combustion processes.

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